OUR GREATEST TRAVELERS 
problems of the migration student. A 
favorite theory of the past, and one still 
claiming many advocates, is that river 
valleys and mountain chains form con- 
venient highways along which the birds 
travel in the spring, and which are easily 
recognized on the return trip. 
The incorrectness of this theory (at 
least with reference to some species) is 
proven by the migration routes of the 
palm warblers. They winter in the Gulf 
States from Louisiana eastward and 
throughout the Greater Antilles to Porto 
Rico. They nest in Canada from the 
Mackenzie Valley to Newfoundland. To 
carry out the above theory, the Louisiana 
palm warblers should follow up the 
broad, open highway of the Mississippi 
River to its source and go thence to their 
breeding grounds, while the warblers of 
the Antilles should use the Alleghany 
Mountains as a convenient guide. 
As a matter of fact, as shown on the 
map, page 186, the Louisiana birds nest 
in Labrador, and those from the An- 
tilles cut diagonally across the United 
States to summer in central Canada. 
The two routes cross each other in Geor- 
gia at approximately right angles. 
Another idiosyncrasy of bird migra- 
tion is the adoption by the Connecticut 
warbler of different routes for its south- 
ward and northward journeys. All the 
individuals of this species winter in 
South America, and, as far as known, all 
go and come by the same direct route 
between Florida and South America, 
across the West Indies; but north of 
Florida the spring and fall routes. di- 
verge. The spring route (page 186) 
leads the birds up the Mississippi Valley 
to their summer home in southern Can- 
ada; but fall migration begins with a 
1,000-mile trip almost due east to New 
England, whence the coast is followed 
southwest to Florida. 
The Connecticut warbler is considered 
rare, but the multitudes that have struck 
the Long Island light-houses during Oc- 
tober storms show how closely the birds 
follow the coast-line during fall migra- 
tion. 
The map represents the spring-migra- 
tion route as far as at present known. 
MIGRATION ROUTE OF THE CLIFF SWAL- 
LOWS THAT NEST IN NOVA SCOTIA 
(SEE PAGES 184 AND 193) 
The swallow, unlike the warbler, travels 
by day. 
The fact that the route is practically 
north and south through Ohio and then 
turns abruptly west indicates a large and 
as yet undiscovered breeding area in On- 
tario north of lakes Huron and Superior. 
Indeed, so little is known about the nest- 
ing of the Connecticut warbler that the 
eggs obtained by Mr. Seton more than 
25 years ago still remain unique. 
Incidentally, this route of the Connec- 
ticut warbler is a conclusive argument 
against the theory that migration routes 
indicate the original pioneer path by 
which the birds invaded the region of 
their present summer homes. 
THE LONGEST CONTINUOUS FLIGHT IN 
THE WORLD—2,500 MILES 
Such elliptical migration routes as that 
mentioned above are rare among land 
birds, but are used and on a far larger 
scale by many water birds, notable 
among which is the golden plover. This 
species nests along the Arctic coast of 
North America, and as soon as the young 
are old enough to care for themselves 
fall migration is begun by a trip to the 
Labrador coast, where the plover fat- 
tens for several weeks on the abundant 
native fruits. A short trip across the 
Gulf of St. Lawrence brings it to Nova 
Scotia, the starting point for its extra- 
ordinary ocean flight, due south to the 
coast of South America (page 180). 
